Human nerve tissue includes regions which may be stimulated with optical radiation. Such stimulation may result in neural and/or metabolic response which may manifest itself as a difference in circadian rhythm, mental agility and/or abundance of hormones and physiological transmitters. A symptom associated with insufficient sunlight is known as SAD (Seasonal Affective Disorder).
The symptoms associated with insufficient sunlight may be reduced with artificial illumination installations which may be located in homes and/or working facilities. The artificial illumination installations are, however, large in size and are therefore virtually fixed to the operating environment. Furthermore, the artificial illumination installations require a large amount of power, and the efficiency is low.
Therefore it is useful to consider techniques for providing optically sensitive nerve tissue with optical stimulation.